The impact of extrusion on the nutritional composition, dietary fiber and in vitro digestibility of gluten-free snacks based on rice, pea and carob flour blends

Abstract

Consumers and the food industry are demanding healthier products. Expanded snacks with a high nutritional value were developed from different rice, pea and carob flour blends. The proximate composition, starch (total and resistant), amylose and amylopectin, dietary fiber (soluble and insoluble) contents, and the in vitro protein digestibility of different rice-legume formulations, were evaluated before and after the extrusion process. Compared with the corresponding non-extruded blends (control), the extrusion treatment did not change the total protein content, however, it reduced the soluble protein (61-86%), the fat (69-92%) and the resistant starch contents (100%). The total starch content of all studied blends increased (2-19%) after extrusion. The processing increased the in vitro protein digestibility, reaching values around 88-95% after extrusion. Total dietary fiber was reduced around 30%, and the insoluble fraction was affected to a larger extent than the soluble fraction by the extrusion process. Because of its balanced nutritional composition, high dietary fiber content, as well as low energy density, these novel gluten-free snack-like foods could be considered as functional foods and a healthier alternative to commercially available gluten-containing or gluten-free and low nutritional value snacks.

Cocoa husk application in the enrichment of extruded snack products

“…After extrusion, due to high shear and high temperatures, starch granules are damaged and starch is leaching, partly or completely gelatinizing and melting. It is becoming susceptible to physical damage and hydrolysis, as well as more accessible to enzymes that can rapidly hydrolyze it to glucose (Arribas et al, ; Sopade, ). Consequently, the RS content in extruded samples dropped to between 0.17% (in the control sample) and 0.40% (in the sample with 15% of cocoa husks).…”

Healthy novel gluten-free formulations based on beans, carob fruit and rice: Extrusion effect on organic acids, tocopherols, phenolic compounds and bioactivity

“…Flours with different ratios of rice, beans and carob fruit were prepared in order to obtain six formulations. The different proportions of each flour were selected according to previous studies (Arribas et al, 2017;Varela et al, 2007) in order to obtain extrudates with adequate technical characteristics (expansion index and bulk density) (data not shown). The mixtures included calcium carbonate and salt to improve the texturisation and flavour, respectively (Table 1).…”

“…In previous studies (Arribas et al, 2017;Arribas, Cabellos, Cuadrado, Guillamón, & Pedrosa, 2019), it has been reported that the extrusion of rice, pea and carob fruit blends enable the making of nutritious and phytochemical-rich food products that are suitable for establishing a healthy lifestyle. However, it has not been evaluated for the potential bioactivities, such as cytotoxicity, anti-inflammatory and antimicrobial.…”

Inclusion of limited amounts of extruded legumes plus cereal mixes in normocaloric or obesogenic diets for rats: effects on intestinal microbiota composition

“…Finally, an extract of pea albumins led to an anti-inflammatory effect at the colon level in mice, accompanied by a modulation in the composition of the intestinal microbiota, [30][31] and dark kidney beans or cranberry bean supplements suppressed colonic inflammation and reduced the severity of DSS-induced colitis in mice. [32][33] As explained in the accompanying paper, 34 new highly palatable extruded mixes of legumes plus cereals similar to a snack food have been produced 35 and incorporated in limited amounts into normocaloric or obesogenic diets for rats. Our purpose was to evaluate the effects of dietary incorporation of this new food ingredient on lipids (accompanying paper 34 ) and intestinal microbiota composition (current paper).…”